Around the past year or so I've sort of (re-)dumbed down to the habit of practicing my arithmetic skills. Here's a link (http://www.jimmyr.com/blog/speed_math.html) to a speed trainer.

My preliminary speeds are around:

1 sec for simple addition
2-3 sec for intermediate addition

1-2 sec for simple multiplication
8-15 sec for intermediate multiplication

Try and see how you stack up...

2.27 avg (simple addition)
7.1 avg (medium addition)

1.8 avg (simple mutliplication)
6.12 avg (medium multiplcation)


Allthough I got 100% correct answers, those timings make me feel kinda retarded.

basic addition - 1.7 Seconds avg.

hard addition - 7.3 seconds avg.

master addition - 9.39 seconds avg.


didnt do the rest i got bored,


peace.

1.93s basic add
4.33s medium add
1.97s basic mult

Not bad, not bad.

Crunchycat, do you use the cross-multiplying method for the intermediate multiplication? Or is there something that works faster?

Not bad, not bad.

Crunchycat, do you use the cross-multiplying method for the intermediate multiplication? Or is there something that works faster?

I wasn't using any particular method other than trying to keep the number simple. It probably isn't too efficient but I've never trained myself at speed caculations in my head.

For example, the way I would process 92 x 15 is:

92 * 10 = 920
92 * 5 = 92 * 10 / 2 = 920 / 2 = 460
920 + 460 = 1380

The way I would process 52 * 25 is:

52 * 10 = 520
52 * 20 = 52 * 10 * 2 = 1040
52 * 5 = 52 * 10 / 2 = 520 / 2 = 260
1040 + 260 = 1300

The way I would process 8 * 33 is

8 * 30 = 240
8 * 3 = 24
240 + 24 = 264

After about 45 games, I got about 63 stars - rating "Uber." My fastest 3X3 multiplication is down to about 20-40 seconds. My 2X2 multiplication is still about 8-15 seconds.

I wonder how fast someone with the mental abacus technique would do.

I think the fastest way is to memorize all 2x2 multiplications, like we do with 1x1. Then 3x3 and 4x4 would be just like 2x2.

Oh yeah, should memorize all 2x2 additions too, in order to handle 3x3.

I think the fastest way is to memorize all 2x2 multiplications, like we do with 1x1. Then 3x3 and 4x4 would be just like 2x2.

Oh yeah, should memorize all 2x2 additions too, in order to handle 3x3.

Tell me if you have any success at the memorization of 2X2 multiplications and 2X2 additions. I might try it as well.

You guys do realize there is no point to memorizing 2X2 multiplications or whatnot since the set of integers is infinite

There is some point, for making calculations with more significant digits easier to do.